Automotive trim strips have been formed of laminates that give an appearance of bright metallic strips. A typical laminate includes a thin strip of polyester material bearing a layer of metallic material and bonded to a substrate of a polyvinyl chloride (PVC) material. The metallic layer is vacuum deposited on the polyester material, which is a thermo-setting resin that is not plasticizable upon heating. One or several polyester strips can be bonded to a single PVC substrate, and many different widths and cross-sectional configurations can be used, depending on the visual and functional effects desired. Such automotive trim laminates are made by extruding the PVC substrate, bonding one or more polyester strips bearing a metallic layer to the PVC substrate to form a laminate that is cooled and later mounted on a support panel. Such strips can have protective exterior resin coatings and can be mounted along the outside of an automobile or truck body, and they can also be mounted on inside door panels, dashboards, seats, and other places in the interiors of automobiles and trucks.
The visual appearance of metalized plastic automotive trim strips requires uninterrupted uniformity in the smoothness and highly polished appearance of the metallic layer that is visible through the polyester material. For automotive design purposes, it is also desirable to mount such automotive trim strips along curved paths as well as straight paths, and this leads to problems solved by the invention.
The usual way of mounting metalized plastic automotive trim strips to an interior door panel, for example, is to hold the trim strip accurately in place on the door panel with a holding die while the strip and its support surface are heated, preferably by dielectric heating, to thermally bond the trim strip to the door panel. Automotive design also requires that the mounted trim strips fit accurately to the desired path and remain securely attached and dimensionally stable throughout the temperature extremes likely to be encountered by an automobile.
When trim strips made according to prior art methods are thermally mounted along curved paths disfigurement occurs that spoils their appearance. The radially inner edge of a curved trim strip develops slight irregularities or tiny wrinkles that appear to be defects and spoil the otherwise smooth metallic appearance.
The invention involves recognition and study of the causes and possible solutions of the problems of mounting metalized plastic automotive trim strips along curved paths. The invention proposes a simple and effective way to make a metalized plastic automotive trim strip so that it is thermally mountable along a curved path without spoiling the uniformity of its appearance. The inventive solution also aims at economy, simplicity, and effectiveness in meeting all automotive design requirements for metalized plastic automotive trim strips while allowing such strips to be thermally mounted along curved paths.